EP1486328A2 - Intaglio printing machine with a screen cylinder - Google Patents

Abstract

The printing machine has a printing plate cylinder (2), a printing cylinder (1) and at least one screen printing cylinder (7), for transfer of screen printing ink to the printing plate cylinder, provided with a printing plate having different recesses for reception of the intaglio printing ink and the screen printing ink, the recesses for the screen printing ink having a larger size.

Description

The invention relates to an intaglio printing machine according to the preamble of Claim 1.

EP 03 43 106 A2 describes a printing press with one on a forme cylinder arranged intaglio printing plate and a printing cylinder in which the Intaglio printing plate at the same time as wet offset printing plate for an additional Offset printing unit can serve.

A printing press with an intaglio printing unit with forme cylinder and impression cylinder is also known from EP 03 51 366 B1. The gravure printing unit is in this printing press combined with an indirectly working printing unit, from which printed sheets with With the help of an intermediate sheet transport device.

Printing machines of this type allow printing on top of one another with different ones Techniques on the same substrate with a high degree of registration. she are therefore preferred for printing documents that have a high degree must be secure against counterfeiting, such as banknotes, securities, ID documents etc.

EP 08 64 421 A1 describes a printing press with exchangeable ones Ink application devices for different printing processes.

EP 05 63 007 A1 shows an intaglio printing machine on its plate cylinder in addition to the stencil cylinder attached to the cylinder Stencil cylinder is employed.

DE 197 46 268 A1 discloses paints of different viscosities different printing processes.

GB 511 049 A describes a printing press in which an engraved Plate cylinders are assigned to screen printing cylinders.

The invention has for its object to provide an intaglio printing machine.

The object is achieved by the features of claim 1.

The advantages that can be achieved with the invention are, in particular, that they are Print tactile features easily and with high registration accuracy in relation to other print motifs. The attachment of such tactile motifs is particularly desirable for banknotes, in order to include a visually impaired person enable safe detection of banknotes and differentiation of their denominations.

The pressure plate of the forme cylinder of such a machine advantageously has Wells, which are not just wells for receiving one Ink can act, but also screen printing ink targeted in such depressions can be introduced to them subsequently with one of the shape of the recess to print the corresponding profile.

The gravure printing process carried out with the printing press is preferably a batch printing process, i. H. there is a collecting cylinder on which different inks to be printed independently of each other, preferably with the help of template cylinders, and so created complete gravure motif in a single slit passage on the Substrate is transferred.

According to a first embodiment, the screen printing cylinder is on the forme cylinder arranged. In terms of the direction of production, it can be behind one for the Gravure printing device known per se can be arranged so that the Screen printing process takes place essentially unaffected by gravure printing. The However, screen printing cylinders can also be attached to the form cylinder before such Wiping device can be arranged so that the screen printing ink in a corresponding manner how to wipe the ink.

According to a second embodiment, the screen printing cylinder is on the collecting cylinder arranged and applied the screen printing ink to this first.

Embodiments of the invention are shown in the drawings and are in following described in more detail.

Fig. 1

einen schematischen Schnitt durch eine erste Ausgestaltung der Druckmaschine;

Fig. 2

einen entsprechenden Schnitt durch eine zweite Ausgestaltung;

Fig. 3

die Oberfläche einer in der Druckmaschine verwendeten Tiefdruckplatte im Schnitt;

Fig. 4 und Fig. 5

einen Schnitt durch eine dritte bzw. vierte Ausgestaltung der Druckmaschine;

Fig. 6 und Fig. 7

jeweils einen Teilschnitt durch einen Siebdruckzylinder.

Show it:

Fig. 1

a schematic section through a first embodiment of the printing press;

Fig. 2

a corresponding section through a second embodiment;

Fig. 3

the surface of a gravure plate used in the printing machine in section;

4 and 5

a section through a third or fourth embodiment of the printing press;

6 and 7

each a partial section through a screen printing cylinder.

The design of the printing press shown in schematic section in FIG. 1 has a plurality of inking units 8, each with a stencil cylinder 4 interact and color on raised areas of the assigned Transfer template cylinder 4. The template cylinders 4 in turn act with one Collection cylinder 6 together, on which they receive the ink received by the inking units 8 transfer. In this way, a multicolored pattern is formed on the collecting cylinder 6 generated, the colored zones of each of the raised areas of the template cylinder 4 correspond.

The collecting cylinder 6 in turn acts with a forme cylinder 2, e.g. B. one Plate cylinder 2 together, on the gravure plates, in particular Steel line printing plates are mounted. These pressure plates are in contact with the Collection cylinder 6 colored according to the color pattern formed on the latter, the ink passing through the gap between plate cylinder 2 and Collecting cylinder 6 is essentially pressed into etched or engraved fine channels, that correspond to a detailed pattern to be printed on the substrate. In Production direction, d. H. clockwise in Fig. 1, behind the gap is one Wiper device 3 arranged, those portions of the ink that are in the fine channels have not found a place, removed from the surface of the plate cylinder 2.

Following the wiper device 3 is on the circumference of the plate cylinder 2 Screen printing cylinder 7 arranged a screen printing unit. This carries a screen printing ink on the printing plates pre-inked and wiped with the printing ink Plate cylinder 2 on.

In a subsequent gap 9 in the production direction between the Plate cylinder 2 and a pressure cylinder 1, the totality of the Printing cylinder 2 applied colors on a printing material, in particular on Printed paper sheets, the gap 9 by a (not shown) conveyor are fed.

The printing machine thus generates a complete intermediate image on the plate cylinder 2, that contains all the colors of the image to be printed and in one Gap passage is transferred to the substrate. This arrangement allows the Screen printing pattern with an extremely high degree of accuracy in relation to that Position rotogravure patterns on the printing plates and so one degree To achieve registration in two steps by promoting the Printing processes separate printing is not feasible.

In this printing machine one expediently becomes a screen printing ink with a high viscosity compared to that lying on the surface of the impression cylinder 1 Choose gravure ink to avoid being on the flat surfaces of the printing plates applied screen printing ink when passing through the gap 9 to an undesirable extent is flattened, which could lead to an unclean print image and the tactility of the screen print pattern on the finished printed product.

2 differs from that of FIG. 1 by the arrangement of the screen printing cylinder 7 in the production direction behind the collecting cylinder 6 and in front of the Wiper device 3. FIG. 3 shows a section of a pressure plate for use in this press. Their surface ranges between plan, not printing Areas 13 each have fine channels 11 and larger depressions 12. The channels 11 can cross the depressions 12. The channels 11 each serve to receive printing ink from the collecting cylinder 6, whereas the larger recesses 12 for receiving Screen printing ink are provided. When passing through with printing and screen printing ink Colored plate cylinder 2 by the wiper device 3, the flat areas 13 of the printing plate freed of color, whereas in the channels 11 or depressions 12 the applied color remains and when passing through the gap 9 on the Substrate is transferred. As you can see, with this configuration they are wearing Printing plates not only the gravure pattern, but also that of screen printing. On Flattening areas of the printing plates inked with screen printing ink Passage through the gap 9 is excluded in this embodiment because the im Gap 9 effective contact pressure between the flat areas 13 of the pressure plate and the printing substrate or the printing cylinder 1 prevents the screen printing ink from Wells 12 escape laterally. The screen printing ink is therefore based on a contour applied the substrate that corresponds to the depth profile of the recesses 12. It a very accurate and reproducible print image can be created.

In the modification shown in FIG. 4, the screen printing cylinder 7 is in the production direction arranged in front of the collecting cylinder 6. This has happened when using a pressure plate As shown in FIG. 3, the consequence is that the depressions 12 have already been filled with screen printing ink when inking takes place. As a result, when applying the Screen printing ink on the printing plate in the recesses 12 no printing ink is a color alienation of the screen printing ink by printing ink on finished printed product largely excluded.

Fig. 5 shows a further embodiment of the printing press, which is different from the above described differs in that the screen printing cylinder 7 on the collecting cylinder 6 is arranged instead of on the plate cylinder 2. It can there, as shown in the figure, based on the direction of production in front of the template cylinder 4, or behind them be arranged. In this embodiment, too, the plate cylinder 2 passes through applied screen printing ink the wiper device 3, the effects and advantages of this Design therefore essentially correspond to those with regard to the Embodiments of FIGS. 2 and 4 have been described.

Fig. 6 shows in a partial section a structure of the screen printing cylinder 7, which in particular 1, 2 and 4, it is advantageous if the plate cylinder 2 Has circumferential areas that deviate from the exact cylinder shape, for. B. due from there arranged sheet grippers 21. Fig. 6 shows the vicinity of the gap that the Screen printing cylinder 7 forms with the plate cylinder 2. The screen printing cylinder 7 has in each case at its axial ends a support ring 14, on the outer circumference of a sieve 16, e.g. B. is spanned from silk or polyamide gauze or bronze wire mesh. in the Inside the screen printing cylinder 7 is a doctor blade 17, the position of which is in the radial direction Direction, d. H. in the horizontal direction in the figure, through a curved body, here one on the end faces of the screen printing cylinder 7 formed guide slot 18 controlled through which a cylindrical guide extension 19 of the doctor blade 17 extends.

Outside the screen printing cylinder 7, the guide extension 19 is on both sides in the direction the axes of rotation of the two cylinders 2; 7 connecting line 20 slidably mounted. The Figure shows the doctor blade 17 in a position in which the sheet gripper 21 of the plate cylinder 2 the gap between the two cylinders 2; 7 passes through. Opposite the bow gripper 21 the screen 16 has a radially inwardly indented peripheral section 22. The Guide slot 18 has a not shown in the figure, for cylindrical outer surface of the sieve 16 concentric circular arc-shaped section 23 and an inwardly indented section 24, the course of which Corresponds to circumferential section 22. The course of section 24 is selected such that if the section 24 during the rotation of the screen printing cylinder 7 on the guide extension 19 moved past, the squeegee 17 is pulled back so far that it only exerts a minimal pressure on the screen 16 which does not result in any noteworthy Deformations of the screen 16 in the peripheral portion 22 results, or that they are in contact with completely loses the screen 16 and therefore no pressure on the peripheral portion 22 thereof exercises, which could deform it and damage it during operation. If on the other hand, the guide extension 19 passes through in section 23 of the guide slot 18, presses the doctor blade 17 against the inside of the screen 16 in such a way that one on the doctor blade 17 Color 26 is pressed through the open areas of the screen 16 and on is applied to the plate cylinder 2 in this way.

The embodiment of the screen printing cylinder 7 shown in FIG. 7 is suitable if the Plate cylinder 2 no areas projecting over the radius of the printing plates, but at most has a concave section such as a channel 27. The Screen printing cylinder 7 is cylindrical over its entire circumference without one indented section. As in the case of the screen printing cylinder 7 from FIG. 6, it is inside of the screen printing cylinder 7 shown here, a doctor blade 17 is arranged, which is a pasty Paint 26 passes through the screen 16 stretched on the screen printing cylinder 7 and thereby exerts pressure radially outward on the screen 16. As long as the common Rotation of screen printing cylinder 7 and plate cylinder 2, the screen 16 the surface of the Touches plate cylinder 2, this provides a back pressure, which is a deformation of the Siebs 16 prevented by the doctor blade 17. To avoid such deformation in the area of To prevent channel 27 where the screen 16 is not in contact with the plate cylinder 2, a support element 28 is arranged radially inside the sieve 16, which is located in Circumferential direction of the screen printing cylinder 7 over a peripheral portion 29 of the screen 16 extends, which corresponds to the expansion of the channel 27 on the plate cylinder 2. The Support element 28 is a closed plate which is curved in the form of a cylinder segment made of metal or strong plastic.

The support element 28 is mounted radially inside the sieve 16, and leading End 31 and trailing end 32 of screen 16 overlap each other in that Support element 28 supported peripheral portion 29. In this way, the sensitive Connection between the two ends 31; 32 before contact with the squeegee 17 and thus protected against premature wear.

In this construction of the screen printing cylinder 7, the doctor blade 17 is guided with a Guide bodies such as the guide slot 18 from FIG. 6 are not required. Instead, the doctor blade 17 can move radially slightly against the force of a spring be displaceable or have a lip 33, the deformation of which is slight Radius fluctuations can compensate. To with such a construction Transition of the doctor blade 17 from the screen 16 to the support element 28 and back to the To facilitate screen 16 and to avoid synchronism of the screen printing cylinder 7, the support element 28 is provided with a leading edge 34 and a trailing edge 36 which are chamfered in the circumferential direction of the screen printing cylinder 7 and not exactly parallel to a generating the outer surface of the screen printing cylinder 7 or to the lip 33 of the doctor blade 17, but at a small angle to it.

LIST OF REFERENCE NUMBERS

1

pressure cylinder

2

Forme cylinder, plate cylinder

3

wiper

4

stencil cylinder

5

-

6

collecting cylinder

7

screen printing cylinder

8th

inking

9

gap

10

-

11

channel

12

deepening

13

Area, planner

14

support ring

15

-

16

scree

17

doctor

18

guide slot

19

Guide extension

20

line

21

sheet grippers

22

peripheral portion

23

section

24

section

25

-

26

colour

27

channel

28

support element

29

peripheral portion

30

-

31

End, leading

32

End, lagging

33

lip

34

run-up edge

35

-

36

trailing edge

Claims (1)

Intaglio printing machine with a forme cylinder (2) and a printing cylinder, the forme cylinder (2) being assigned a collecting cylinder (6), characterized in that at least one screen printing cylinder (7) is arranged on the collecting cylinder (6).

Images